Supposing the Republicans should abandon their principles, which seem to be the terms upon which peace is offered, and, in 1864, the Democrats should succeed in electing the President upon the slave-extension platform, and the Republicans, feeling that their interests were likely to be trampled upon by the dominant party, should say to the Democracy that, unless said Democrats would abandon the principles of their party, and secure the Republicans against the exercise of their principles in the future, by an amendment to the constitution itself, they (the Republicans) would dissolve this Union? It will be observed that, if one party has the right to demand concessions, the other party has the same right, consequently it would not be the majority that would rule, but the minority. Neither have we any guarantee that, by granting the present demands, that other and still more absurd and threatening demands will not be made. We are now called upon to incorporate into the constitution certain additional rights and privileges for slavery; and what is the threatened penalty that is offered to the freemen of this nation if they fail to grant what is demanded? Why it is nothing less than a complete overthrow and destruction of this government--and yet the Republicans are taunted with the charge of being the cause of all the consequences of the great calamity that seems awaiting our destruction. I call especial attention to this subject, more particularly in consequence of the probable effort that will be made to force what is called the "Crittenden Amendment," upon the people. It should be remembered that Mr. Crittenden proposes, not only to give all the territory south of 36° 30' to the slave interests, but all the territory hereafter acquired. The restoration of the Missouri Compromise sounds very smooth and pleasant to the ear, but is it the Missouri Compromise that Mr. Crittenden proposes to restore? Far from it. Let us look at the broad difference between the two measures, and see whether there is not something that looks as though there was deception, of the deepest dye, about to be practiced upon those who are desirous of preserving the territories free from the blighting curse of slavery. We have heard much about the Missouri Compromise, also about Mr. Crittenden's amendment, and, for the benefit of those who are not familiar with the two measures, we will give them both in full. The following is all that relates to the institution of slavery in what is called the Missouri Compromise: